2m9 `K]f*F gaR It is stated that traveling cables are to be suspended at the car and hoistway ends, or counterweight end where applicable, so as to reduce the strain on the individual copper conductors to a minimum. CLAIMED . The article stands apart from the rest of the code in the sense it exempts these categories of circuits from the general requirements for wiring in most occupancies, found in Chapter 3. If power is not being supplied to the elevator controller (e.g., open mainline fuses, etc. However, this can vary depending on building conditions and exterior grade. If a hydraulic elevator loses power because a heat detector goes off or for any other reason it could trap occupants for an unpleasant amount of time. This will normally require you to vent the room with a fire/smoke damper and include smoke detector signals in the control logic. Luminaires must be lensed or equipped with wire guards to protect the lamps. Accordingly, the supply wires are protected only for short circuit, and the overload protection is provided closer to the motor. These are the individual branch circuits required for car lighting, receptacles, auxiliary lighting and ventilation on each elevator car; individual branch circuits for machine-room and similar location lighting and receptacle; and branch circuits for hoistway pit lighting and receptacle(s). The electrical conductors and equipment for non-mine elevators that extend below grade are under NEC jurisdiction. In driving through commercialized suburban areas, you frequently see paralleled conductors for large retail grocers (where there is a heavy refrigeration load). To address this issue, Code Making Panel (CMP) 12 of the National Electrical Code acted on several proposed changes to Article 620 during the revision cycle for the 2017 NEC that deal with the proper installation of elevator controllers. ), a duplex 15A 120-volt receptacle in pit with ground- fault circuit protection and a 15A 120-volt Non GFCI receptacle for the sump pump. It employs specialists in Mobile, Alabama, and has technical and news correspondents around the world. Machine room/control space lighting and receptacles 4. Personal protective equipment (PPE): Use appropriate PPE to protect body parts within the range of 3-16 in. It is important to note, that these selective coordination tables can indicate a lack of selective coordination at a given fault current for circuit breakers that do not show overlap on the time-current curves of the circuit breakers. He has focused on writing since 2006, having written for such magazines as ELEVATOR WORLD, Electrical Construction and Maintenance, Cabling Business, Electrical Business, Nuts and Volts, PV Magazine, Electrical Connection, Solar Connection, Solar Industry Magazine, Fine Homebuilding Magazine and Engineering News. The idea is quite simple. First, you'll need to install lighting in the elevator equipment room (Photo 1) and shaft pit (Photo 2). As always, the best advice in all instancesdo your homework, communicate often, and document decisions made. The traveling cable or raceway is also permitted to include shielded conductors and/or one or more coaxial cables. However, when I've put in elevators, NEC seems to always take a back seat to ANSI, which seems . Dec. 21, 2010. Convenience receptacles and lighting for maintenance purposes are required at the base of the pit and, in some instances (elevator manufacturer dependent), at the top of the elevator shaft. A few years later, in 1880, Werner von Siemens built the first electric elevator, setting the stage for a new industry that would change the world by making the practical use of tall buildings possible. Please check your entries and try again. The most complex of these is the elevator. Home Articles Elevator World June 2012 Issue NEC Article 620: Elevators, Part 2. z, /|f\Z?6!Y_o]A PK ! This is something that can be easily accomplished if the elevator controller manufacturer uses components in combination with overcurrent protective devices that are tested and listed with high combination SCCRs. There are several actions that could trigger this block including submitting a certain word or phrase, a SQL command or malformed data. Section 620.62, Selective Coordination, is central to multi-elevator installations and must be closely observed. For just $7.99 per month, you can gain access to more than 5,000 articles from all Elevator World Publications, this includes EW Global, EW Europe, EW India, EW Middle East, EW Turkey, and EW UK. It states an elevator is permitted to be run by an emergency or standby power system. The Americans with Disabilities Act Accessibility Guidelines for Buildings and Facilities (ADAAG) now require the cab to have a special phone accessible by individuals with disabilities. NEC Article 620 Part VI, Disconnecting Means and Control, is rather exacting. The electrical system designer calculates the maximum available fault current at the elevator controller. This room is to be secured against unauthorized access (kept locked). Weight (passengers, freight, car and attendant machinery) may be fairly substantial, and speed is significant. You may go up to 600 V for power circuits supplying door-operator controllers and door motors, branch circuits and feeders to motor controllers, driving-machine motors, machine brakes and motor-generator sets. Section 620.37 re-emphasizes that only wiring used in connection with the elevator is permitted within the hoistway, machine room, control room/machinery space or control space. GFCIs in elevator pits During an inspection of the elevators in a commercial building, the state inspector failed us for using a GFCI-type circuit breaker to protect a receptacle in the elevator pit. All elevator hoistways must be equipped with a sump pit located at the rear of the elevator pit. It is mandatory, as in the car, that these items have a separate, dedicated branch circuit, and the required lighting is not to be supplied through a GFCI. You'll be responsible for specifying the items related to the fire alarm and some controls, as well as supplying lighting and power to the equipment room and elevator pit. It begins by considering metal and nonmetallic wireways. Such vehicles include, but are not . After reading this article, you should have learned about: The meanings of definitions for control room and control space versus machine room The purpose and specifications for working spaces Insulation types and minimum sizes of conductors Requirements for feeder and branch-circuit conductors Feeder demand factors for ele-vators. We have circuited the receptacles and lights in the pits to the same circuit. While machine room-less designs have been commercially available for many years, their use may still be unknown to some AHJs. Finally, typical installations and compliance with all these requirements will be discussed. For elevators that regenerate power back into a power source unable to absorb the regenerative power under overhauling elevator load conditions, a means to absorb this power is to be provided. Proper selective coordination in a multi-elevator installation on the same feeder ensures if one elevator develops a fault, the other units will not be shut down. The fire loading resulting from an accumulation of abandoned low-voltage cabling may be considerable, and has to be understood and dealt with. Elisha Otis safety elevator, introduced in 1853, prevented the fall of the car if the cable broke. The proposals resulted in adding new requirements in the 2017 NEC for: Marking the elevator controller short-circuit current rating (SCCR) by the elevator control-ler manufacturer. An example would be the elevator, as well as all wiring in a utility-owned administration building. In Part One of this series (ELEVATOR WORLD, April 2012), we began an examination of National Electrical Code (NEC) 2011 mandates for elevators and related equipment installations. For circuit breakers, time-current curves must be consulted as well as the circuit breaker manufacturers selective coordination tables. [emailprotected] Choose topics from a full list of courses covering electrical topics that cover what you need to know from the NEC and other electrical codes and standards. Modern electronic elevator controls can be sensitive to temperature shifts. The Uniform Building Code requires two-way communications between the central command center and the elevators, each elevator lobby, emergency power rooms, and by entries into enclosed stairways (Section 403.5.3). Traveling cables are to be approved for hazardous locations and must comply with the appropriate sections for each hazardous-location class that covers use of flexible cords. Selective coordination is defined by the NEC as: Localization of an overcurrent condition to restrict outages to the circuit or equipment affected, accomplished by the selection and installation of overcurrent protective devices and their ratings or settings for the full range of available overcurrents, from overload to the maximum available fault current, and for the full range of overcurrent protective device opening times associated with those overcurrents.. In these installations, it is best to design the elevator controller so the elevator controller SCCR is adequate for the available fault current. A traditional elevator installation (which includes a machine room) requires access inside the elevator shaft. Power for the elevator controller must first enter a lockable safety disconnect device, located adjacent to the door of the equipment room. Many NEC articles address voltage limitations, and Article 620 is no exception. All Rights Reserved | Contact Us | Privacy Policy. The condition is that all conductors must be insulated for the maximum voltage applied to any conductor within the cables or raceway system, and all live parts of the equipment must be insulated from ground for this maximum voltage. In this case, it may be best if the elevator controller manufacturer does not include the elevator disconnecting means (often offered as a circuit breaker) but instead have the installer provide a separate fused disconnect to comply with NEC 620.51(A) and also achieve a high SCCR for the elevator controller when fuses are provided as specified by the elevator controller and marked on the elevator controller nameplate. Based on the analysis, the arc-flash boundaries at the elevator/escalator controllers ranged from 3-16 in. Three wiring categories within hoistways are allowed in addition, each with exceptions. hb``` ea``j~p2nfH 'xXg00,/(_ Iq8PDdg-~ s$!XI;Fn0vu `h`R 1y 0B.":9.@, e`xI;=7O3fvbb8:SC;%O*20] In the event of a breakdown, that phone must automatically call a location staffed 24 hours a day. Elevator power disconnect (with utility feed marking) located in the machine room or other permitted location. The disconnecting means is to be located adjacent to or an integral part of the motor controller. Cylinders in hydraulic elevators usually aren't suitable for buildings taller than five stories. In contrast to the lighting, these receptacles must be connected to GFCI devices. wide or the width of the equipment, whichever is greater. Any other utilization equipment associated with the elevator The disconnecting means is to be an externally enclosed, operable, fused motor circuit switch or circuit breaker capable of being locked in the open position. He had been with Eaton (Cutler-Hammer and Bussmann) since 1993 and specializes in training on the design and application of overcurrent protective devices and equipment in electrical distribution systems in accordance with the National Electrical Code and equipment in accordance with the various product standards. Notice the definition mentions the full range of operating times. Because of this, several manufacturers offer an all-in-one shunt trip elevator disconnect switch that includes all the prewired accessories needed to comply with the various Code sections. In a time when increasing value is placed on even small amounts of real estate, elevator design must strive to configure, efficiently control and drive elements to whatever degree possible, and that is the thinking behind some alternate locations for these structures. Feeders may be installed within the hoistway where the elevator has a driving-machine motor in the hoistway or on the car or counterweight. In such cases, it's economically justifiable to specify a traction type elevator. A little more narrowly focused (yet of great consequence) is the ubiquitous NEC, which, in the National Fire Protection Association (NFPA)s venerable Handbook edition, devotes 18 double-column pages to electrical design and installation requirements for elevators, escalators and related equipment. These are part of Article 725, Class 1, Class 2 and Class 3 Remote-Control, Signaling, and Power-Limited Circuits. Section 620.85, GFCI Protection for Personnel, provides that 125-V, single-phase, 15- and 20-amp receptacles installed in pits, hoistways, machinery spaces, machine rooms, escalators and moving walks, and on elevator car tops are to be GFCIs. The 12 definitions provided in NEC 2011, Section 620.2 are the place to start for guidance in this area, and the sections that follow lay out implementation guidelines that are very relevant in todays environment. This position paper is written to provide guidance to members whose employees are engaged in elevator-industry work that might expose them to arc-flash hazards, and to assist members in complying with applicable OSHA and National Fire Protection Association (NFPA) standards. If we fast forward more than 36 centuries, we see some important new developments in elevator technology. Conductors supplying a single motor controller are to have an ampacity not less than the motor controller nameplate current rating plus all other connected loads. Even though Edison grasped the basic ideas of fusing and overcurrent protection, many hazards remained. 3. Part III, Wiring, looks at the types of wiring that may be installed in hoistways, cars, machine rooms and related spaces. Article 620 follows this pattern by opening, in Section I, General, with a statement of scope and definitions applicable to the topic under consideration. You need at least one 120VAC GFCI-protected receptacle at each location. The usual scenario for electrical injury is shock when electrical current passes through the human body. +91 8025357028, 2022 Elevator World, LLC. Hazards created by water, snow or condensation in the work area can cause slips, falls and accidental contact. Indeed, most elevator accidents involve maintenance workers, yet even theirs is not an excessively dangerous profession. In some cases, it may require a means to test the shunt trip operation or have one contact operate the shunt trip of more than one elevator. My reasoning comes from 620.24 (A) and (C). This, however, can result in a dramatic increase in cost, space availability (lack thereof), and reduced efficiency. By subscribing, you agree to our User Agreement and Privacy Policy & Cookie Statement. ^W i word/document.xml=nr]6Id=,_$j9-"Y.iGU\h_}. Bonding of elevator rails to a lightning-protection system grounding conductor is permitted, but the conductor itself is not to be located in the hoistway. The feeder OCPD needs to remain closed so the remaining elevators have power and continue to function. No provision is to be made to automatically restore power. The traveling cable, of necessity, is exempted. Besides the power-supply disconnect discussed, it is provided that elevators have a single means for disconnecting all ungrounded car lights, receptacles and ventilation power-supply conductors for that elevator car. Additional requirements concern escape routes. Pits shall be maintained in a clean and dry condition. The elevator equipment room that serves a hydraulic elevator is almost always located on the lowest floor adjacent to the elevator shaft. The basic idea is that there must be a separate, dedicated circuit for car lights, receptacles and ventilation on each car. Please check your entries and try again. Machine room-less elevator installations incorporate the elevator controller and often the primary disconnecting means in a convenient package that is located within the elevator shaft. 974 0 obj <>/Filter/FlateDecode/ID[<64E135C225F1064D91BC8119D14516A9>]/Index[953 36]/Info 952 0 R/Length 105/Prev 204101/Root 954 0 R/Size 989/Type/XRef/W[1 3 1]>>stream !>x=yy Bvv8?~e PK ! Within cars, these additional wiring methods are permitted: The following additional wiring methods are permitted on the car assembly in lengths not exceeding 6 ft.: Within machine rooms, these additional wiring methods are permitted: The following wiring methods are permitted on the counterweight assembly in lengths not to exceed 6 ft.: Having looked at NEC 2011 mandates for elevator and related equipment installations, we will cover wiring methods, overcurrent protection, grounding and other related NEC provisions in part two of this series , running in the April 2012 issue of ELEVATOR WORLD. The basic wiring methods are rigid-metal, rigid nonmetallic or intermediate-metal conduit; electrical metallic or rigid nonmetallic tubing; wireways; or Type MC, MI or AC cable, unless otherwise permitted. The design engineer must identify the available fault current at the elevator controller to the installer so an elevator controller with adequate SCCR can be provided. Below is a summary of these new 2017 NEC sections: In order to comply with these requirements a chain of events must occur. Next, with multiple elevator banks, the controller will usually allow only one elevator at a time to operate, reducing the amount of emergency power required. NEC articles generally adhere to a template, which greatly aids in navigating and quickly locating mandates as needed for project design or, on an installation level, in the field. Even non-composite fiber-optic cable, which does not carry electrical energy, is subject to the code. As stated in Section 7 of the Elevator Industry Field Employees Safety Handbook: Unless it is not feasible, (i.e. There are options available to achieve this depending upon the customers needs. We resume with a look at wiring methods, overcurrent protection, grounding and other NEC provisions as they relate to these installations. Another location that requires a separate branch circuit for lighting and receptacle(s) is the hoistway pit. Dan Neeser is a Senior Field Application Engineer with Eatons Bussmann Division. Hard-service cords and junior hard-service cords are permitted as flexible connections between the fixed wiring on the car and devices on the car doors or gates. All equipment in a machine room-less design is installed within the elevator shaft or exterior compartment near the elevator shaft, including the elevator controller and the elevator disconnecting means. This strategy works to improve the flexibility of the traveling cable, but it is contrary to a general NEC rule concerning the paralleling of conductors, which is generally done in very large sizes to avoid unwieldy wire pulls and terminations. Depending on your local codes, you can do this by installing heat or smoke detectors within 24 in. In all cases, the working space must permit at least a 90 opening of equipment doors or hinged panels. Many new buildings are incorporating an elevator design that does not include an equipment room (sometimes called machine room-less elevators). If you specify a rescuvator, you must also specify a disconnect switch with an auxiliary contact that opens when the disconnect arm moves to the open position, but stays closed when the OCPD trips. Though I understand how someone might argue two. Supports for cables or raceways in a hoistway or in an escalator or moving-walk wellway or platform lift and stairway chairlift runway must be securely fastened to the guide rail, escalator or moving-walk truss, or to the hoistway, wellway or runway construction. In case of emergency, electricians, maintenance personnel and any elevator technicians called in to the premises should have ready access to the key. It is further stressed that no provision is to be made to open or close the disconnecting means from any other part of the premises. +91 8025357028, 2022 Elevator World, LLC. Fireman telephone jacks and telephone cabling are typically sufficient for each of these locations. (g) Stop Switch in Pits. Hydraulic elevator installations are typically supplied from the main switchboard and have an elevator fused switch or circuit breaker in the machine room that serves as the elevator disconnect. (f) Illumination of Pits. The basic requirement is for minimum clear distances of various depths for equipment operating at 600 V or less, nominal, depending upon voltage to ground and lateral distance to insulated or grounded surfaces or exposed live parts (not an issue in elevator machine rooms). Dont troubleshoot unless you can keep your shoe/boot soles dry. But, building codes had been in existence for many centuries. The lighting switch shall be located so as to be readily accessible from the pit access door. -inch conduit is needed to the sump pump. Traction elevators are typically installed in a bank of elevators where fused switches, or circuit breakers in a panelboard are located in the machine room serving the bank of elevators. The action you just performed triggered the security solution. Jul 15, 2021. These must also be insulated for the maximum voltage applied to any conductor within the cable or raceway system. Similar provisions are attached to elevator-car heating and air-conditioning disconnecting means, and to other utilization equipment. All Rights Reserved | Contact Us | Privacy Policy. Article 511 provides the requirements for commercial garages areas used for the storage or repair of self-propelled vehicles that use combustibles (liquid or gas) for power. 354 Morgan Ave. 953 0 obj <> endobj The electrical system designer needs to communicate this information to the person responsible for specifying the elevator controller, which is most often the architect. Thus, the need for door interlock functionality is recognized. However, it is likely that for many elevator controllers, this may not be high enough for the available fault current where they will eventually be installed. Pit light with guard (ten foot candles min. Since 1953, Elevator World, Inc. has been the premier publisher for the global vertical transportation industry. Where the elevator shaft and/or equipment room has a sprinkler fire suppression system installed, the elevator Code requires main line power to the elevator be removed prior to the application of water. David Herres All rights reserved. Use the below learning-reinforcement questions to study for the Continuing Education Assessment Exam available online at www.elevatorbooks.com or on page 111 of this issue. Name the principal code other than NEC that pertains to elevator design/installation. What is the definition of the machine room? Why are voltage limitations important? In which areas must live parts be enclosed? Why are feeder demand factors permitted for multiple elevators? In addition, requirements for selective coordination and shunt tripping should be complied with as needed for the installation. Always verify all conditions and requirements with the state and the AHJ where the installation is taking place. Flexible cords and cables that are components of listed equipment and used in circuits operating at 30 V (42 VDC) or less are permitted in lengths not to exceed 6 ft., provided the cords and cables are supported and protected from physical damage and are of a jacketed and flame-retardant type. Use the below learning-reinforcement questions to study for the Continuing Education Assessment Exam available online at www.elevatorbooks.com or on page 81 of this issue. Which equipment requires a separate branch circuit in the elevator car? Is lighting required to be GFCI protected in the machine room? Where is the lighting switch to be located in the machine room? What is the maximum raceway conductor fill in an elevator hoistway? How many disconnecting means are required for an elevator power supply? For all of this to come together in the real world, there had to be some assurance that these new technologies could be used safely on a wide scale. Where necessary, it is mandated that suitable guards be provided to protect the cables against damage. You are a subscriber that needs to Sign In. Section 620.43, Location of and Protection for Cables, provides that traveling cable supports are to be located so as to reduce the possibility of damage due to the cables coming in contact with the hoistway construction or equipment in the hoistway to a minimum. They must be in enclosures with doors or removable panels that can be locked in the closed position. Moreover, it is necessary to consider future worker safety for an indefinite period. (C) Duplex Receptacle. ,l7CLHmcX9*F -{Q|^"XL`b1y]$,y *R/2Rn{\xG L*vMP.uKW,)68]Y}+ FYS1B=Q0S>Hc 2.2.2.6 . It need not be exactly centered on the equipment, and working spaces of adjacent pieces of equipment may overlap. Marking the elevator controller short-circuit current rating (SCCR) by the elevator controller manufacturer. The AHJ is saying that this is a violation of 620.23. An exception provides that liquid-tight flexible metal conduit or liquid-tight flexible nonmetallic conduit 3/8 in. NEC Article 620 covers elevators, dumbwaiters, escalators, moving walks, platform lifts and stairway chairlifts. Elevator travel is far safer than an automobile trip, and the chance of experiencing disaster is on the order of being struck by lightning in ones own backyard. He is saying that each pit requires a separate circuit, in other words "dedicated". The demand factor ranges from 1.00 for one elevator on a single feeder to 0.72 for 10 or more elevators on a single feeder. But by understanding how these items fit together and what purpose they serve, you can have a successful project. proved for elevator locations - car, hoistway, pit and a-chine roo equireents in Article odify the articles in Chap - ter For eaple, it is stated that the cross-sectional area The code notes that elevator rails or other hoistway equipment are not to be used as the grounding conductor for lightning-protection systems. Electricity is often one of the initial services to fail during a storm. As mentioned, traditional installations of a traction or hydraulic elevator include a separate machine room. h-`7 (Cross-sectional areas of conductors are given in Chapter 9, Tables 5 through 8. Conductors supplying a single motor are to have an ampacity not less than the percentage of motor nameplate current determined from Section 430.22(A) and (E). These selective coordination tables for current-limiting fuses show the minimum amp ratio required between a pair of fuses of a given type(s) to achieve selective coordination. Other requirements: Spa's and Hot Tubs 1996 NEC 15-20 Amp 120 volt Receptacle Requirements for Dwelling units: All outdoor He has focused on writing since 2006, having written for such magazines as ELEVATOR WORLD, Electrical Construction and Maintenance, Cabling Business, Electrical Business, Nuts and Volts, PV Magazine, Electrical Connection, Solar Connection, Solar Industry Magazine, Fine Homebuilding Magazine and Engineering News.
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